Rocket jump ninja is honestly the only mouse reviewer I trust that isn't a pro player (which there aren't many that do regular mouse reviews anyways). The amount of depth that he goes into when doing his reviews is so helpful and is very quick when responding to questions about concerns that people may have when they're about to purchase said mouse

Judging by your criteria, the Steelseries Rival 110 or Steelseries Sensei 310 are choices that you might want to look into. I'd recommend watching the individual reviews regardless of if the mouse is in your price range (which both of them should be) for a better understanding for what you'd be getting if you bought said mouse

Personally I like large mice. But if you want something similar but smaller the FK1 is inexpensive (or it was when I got it, before it became benq zowie, idk if the price has changed at all) steelseries also might have what you want but I think it's a little more pricey.

I use a deathadder chroma because it's large and has a decent hump in the center.

I use the Reddragon Perdition, but then I used to play MMOs, so twelve programmable thumb buttons might be overkill. Makes emoting easy, though.
Had it for three years and no problems yet. Five DPI profiles. It even has adjustable weights.

I use the zowie EC1-A. It is nice for the medium-high sesitivity I use because it has large pads and slides smoothly making micro adjustments easy. If you get a zowie keep in mind that they offer versions that have an elevated back (to support your palm) or ones like the EC series that are highest in the middle.
They also use good sesnors and have low to no lag with universal drivers.

Here to recommend another Zowie mouse. I have the ZA-12 and I love it. It's the exact shape you are talking about. Zowie has incredible sensors and this specific model is really popular with long time gamers like older CSGO and quake pros.

Pair it up with their GSR mouse pad and it's as smooth as can be. I'm a digital artist as well so having precision is really important for me. I've had mine for over a year now and it's been through hell as I've moved about 10 times in this one year and its still going strong too.

Probably a small one, make sure its cute, and wont shit all the time. Sometimes mice can bite, so be aware of that. But a Mus mouse or a Ryukyu mouse would probably be the best. Good luck finding a good pet mouse! Although I dont know why you posted this on an Overwatch webstite

Zowie mice are incredibly popular among esports oriented gamers mainly for their shapes, but keep in mind that the EC mice are ergonomic shapes, not ambidextrous shapes, but I can confidently say that it's honestly one of the best mice shapes out there (which is what zowie mice are already known for anyways)

However you can't rebind any of the buttons since they're plug and play mice with no software. I personally don't mind it since all of my usual functions don't need to be remapped to anything other than their primary functions but I know from using a mouse that previously had a mode switch it was really helpful when in windows and I wanted to open a commonly used program.

The Rival 310 should have those capabilities through the steelseries software that comes with it but once again I'd recommend watching Rocket Jump Ninja's reviews of those mice. Still, if you want an amazing shape, go with the EC2-B. If having remappable buttons is also important to you, go with the rival 310. Either way you've got 2 really good choices to choose from

Razer Abyssus for like 6 years here. Still working fine. Was using Razer DeathAdder be4 it for like 6-7 years aswell (in the end the cabble was "too broken" to repair it, so i switched to abyssus). Can recommend. Abyssus will be also much cheaper than your max budget.